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Unformatted text preview: "Grade or Education" =1 CHEM 2261/01
Summer 08 Exam 1
Chapters 1-3 What is WRONG with the curved—arrow mechanism shown below? Br __ A. The curved arrows connect the wrong atoms; an arrow should connect the O atom in
hydroxide with the Br atom in bromoethane, for example. This mechanism should involve two steps and only one step is shown. B __ C. All of the arrows are drawn backwards (the points and tails are reversed). D The mechanism should only involve two curved arrows instead of the three which are drawn.
E __ . This mechanism shows the wrong reaction products; only ethanol can be produced from this
reaction. Rationale:
Chapter 3 Problem 42 2- Look at the four numbered structures below and pick the choice which designates one of these
structures with its CORRECT E or Z configuration. “sq ,CH-2CH3 H3C\ ICHZBr
IC:C\ /C:C\
CHaCHe CH-ZCHZCI Br CH-ZCH-ZCH-ZCHS
1 g
l?
CHgCH'2C\|‘(|>2 C/CH(CH3)2 CH-SC\ [CHéBr
, = 0:0
_ \
HC=C'CH2 CH-ZCHZCHZ HOCH2/ ‘CHéCHéCI
Z 4 Structure ; has the Z configuration. A
B. Structure 1 has the E configuration.
C Structure 1 has the E configuration.
D None of the choices gives the correct configuration for the corresponding numbered
structure. E. Structure 1_ has the E configuration. Rationale:
Chapter 3 Problem 48 3. Give each atom in the structure below its appropriate formal charge. Choose the CORRECT
statement from the multiple choices. I
I—IZ—I
I-UIJ—I ': The formal charge on B is —1. The formal charge on N is —l. A
B
C. The formal charge on B is O.
D The formal charge on B is +1.
E The formal charge on N is O. Rationale:
Chapter 1 Problem 13d 4- How many primary, secondary, and tertiary carbons does the following compound have? CH'2CH3 CH-ZCIDH-CHS
CH 3 This compound has 2 primary carbons, 7 secondary carbons, and 3 tertiary carbons. This compound has 9 primary carbons, 12 secondary carbons, and 3 tertiary carbons. A
B
C. This compound has 1 primary carbons, 2 secondary carbons, and 3 tertiary carbons.
D This compound has 4 primary carbons, 4 secondary carbons, and 4 tertiary carbons.
E This compound has 3 primary carbons, 6 secondary carbons, and 3 tertiary carbons. Rationale:
Chapter 2 Problem 52-1 5. Given the reaction—coordinate diagram shown below for the reaction of A to give D, choose the
statement which is CORRECT about this reaction. -‘ 'N rrrrg',
l Frz-greu of the ".‘J-ltlllvi‘ A The first step of the reaction is exergonic. B There are three intermediates involved in this reaction. C. A is more stable than D. D There are three transition states involved in this reaction. E The step which converts B to C is the fastest step in the reaction. Rationale:
similar to Chapter 3 Problem 55 5- Determine whether each of the following is a cis isomer or a trans isomer. Choose the CORRECT statement from the multiple choices. H H Br Ber H30 H B'cH CI IU'I The structure labelled i is a cis isomer. The structure labelled i is a cis isomer. A
B
C. The structure labelled ; is a cis isomer.
D The structure labelled ; is a trans isomer.
E The structure labelled 1_ is a trans isomer. Rationale:
Chapter 2 Problem 43 7. Choose a CORRECT name for the compound whose structure is shown below. A (E)—3—(2—ch|oroethyl)—4—methyl—3—hexene
B. (E)—1—ch|oro—3—ethyl—4—methyl—3—hexene
C. (Z)—2,3—diethyl—5—chloro—2—pentene
D (Z)—1—ch|oro—3—ethyl—4—methyl—3—hexene
E (E)—2,3—diethyl—5—chloro—2—pentene Rationale:
Chapter 3 Problem 14C CH lw CH 8- Figure out the number of hydrogens attached to each of the numbered carbon atoms in the following
compound. Choose the CORRECT statement from the multiple choices. morphine The carbon atom numbered 1 has 2 hydrogens attached to it. The carbon atom numbered 5 has 0 hydrogens attached to it. A
B
C. The carbon atom numbered ; has 1 hydrogen attached to it.
D The carbon atom numbered 1_ has 4 hydrogens attached to it.
E The carbon atom numbered g has 3 hydrogens attached to it. Rationale:
Chapter 2 Problem 1 1 9. Water and diethyl ether are immiscible liquids. In a vessel containing both water and ether charged
compounds dissolve in water, and uncharged compounds dissolve in ether. Given that C6H1 1COOH has
a pKa of 4.8 and C6H11NH3+ ion has a pKa of 10.7, which of the following statements is TRUE ? A. In order for both both compounds to dissolve in the water layer the pH of the water layer has
to be between 4.8 and 10.7 B. In order for both both compounds to dissolve in the ether layer the pH of the water layer has
to be below 4.8 C. In order for both both compounds to dissolve in the ether layer the pH of the water layer has
to be between 4.8 and 10.7 D. In order for the carboxylic acid to dissolve in the ether layer and the amine to dissolve in the
water layer the pH of the water layer has to be above 10.7 E. In order for both both compounds to dissolve in the ether layer the pH of the water layer has
to be above 10.7 Rationale:
Chapter 1 Problem 103 10. 11. Draw the most stable conformer of each of the disubstituted cyclohexanes named in the multiple
choices and find the substance in which one of the substituents is in the AXIAL position in the MOST
STABLE conformer. trans—1—ethyl—3—methylcyclohexane trans—1—ethy|—2—methylcyclohexane A
B
C. trans—1—ethy|—2—isopropylcyclohexane
D cis—l—ethyl—3—isopropylcyclohexane
E cis—l —ethyl—3—methylcyclohexane Rationale:
Chapter 2 Problem 67 Expand the condensed structure of the compound with the molecular formula
(CH3) 3C(CH2) 3CH(CH3) 2 and figure out which of the numbered structures below corresponds to
your expanded structure. 'f
H-C—H
'fofo 'f'f'f'f'f'f 'fl'ﬂ'f'f'f'f
H‘9‘9‘ICTC‘9‘9‘9‘C‘R‘9‘H “‘93—‘3—9‘9‘9‘0‘9—H
H HH H H H H H HH H I H H H H
H‘CE—H H—C—H
|
H
1 g H
H 'f
H H-C—H
H\/ T/H H-C—H
HHVHHQCHVHH IHWW flfff
| | | |
H—C—C—C—C—C—C—C—H H—C—c—c—c—c—c—H H-C—C—C—C—c—H
||/\|||| ||I|'_| IIIIH
H HHHc H H H I H H H H H
H/\H H—c—H H—CID—H H-c—H H-c—H
H H H H loo
l-h
| Structure 1_ is the correct expanded structure for this compound. Structure 1 is the correct expanded structure for this compound. A
B
C. Structure ; is the correct expanded structure for this compound.
D Structure ; is the correct expanded structure for this compound.
E Structure i is the correct expanded structure for this compound. Rationale:
Chapter 1 Problem 19d 12. 13. 14. Pick the choice which gives two CORRECT names for the compound whose structural formula is
CH3CH2CH(CH3)NHCH2CH3. Z—butylethylamine and N— sec—butylethanamine ethylisobutylamine and N—ethyl—1—methy|propanamine A
B
C. Z—butylethanamine and 3—methyl—3—pentylamine
D sec—butylethylamine and N—ethyl—Z—butanamine
E butylethylamine and 3—heptanamine Rationale:
similar to Chapter 2 Problem 55c Squalene, a hydrocarbon with molecular formula C30H50, is obtained from shark liver (Squalus is
Latin for "shark.") If squalene is an acyclic compound, how many n bonds does it have? __ A. 4
__ B. 5
__ C. 12
__ D. 6
__ E. 10
Rationale: Chapter 3 Problem 45 What is the hybridization of the indicated atom in the molecule whose structure is shown below? 1 CH3CH=NCH3
__ A sp3d
__ B. sp
__ C. sp3d2
__ D sp3
__ E. sp2
Rationale: Chapter 1 Problem 82e l 5- Look at the three reactions shown below and then look at the pKa table shown below these reactions.
By using the information in the pKa table determine which of the three reactions has the highest
equilibrium constant. CHBCHZOH + NH3 ‘——‘ CHSCHZO' + NH4+ Reaction 1_ CHBOH + NH3 ‘——‘ CHBO' + NH4+
Reaction 2_ CHBCHZOH + CH3NH2 ‘—_‘ CHSCHZO' + CH3NH3+ Reaction 3_ __ A. Since we have to compare "apples" and "oranges" here there is no correct answer to this
problem. Reaction ; has the highest equilibrium constant. B __ C. Reaction 1_ has the highest equilibrium constant. D Reaction 1 has the highest equilibrium constant.
E __ . All three reactions have an identical equilibrium constant.
Rationale:
Chapter 1 Problem 98b 10. 11. 12. 13. 14. 15. Answer Key
"Grade or Education" CHEM 2261/01
Summer 08 Exam 1
Chapters 1-3 1 ...
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